Patterns of variability in DNA content and nuclear volume in regenerating cultures of Nicotiana tabacum

1983 ◽  
Vol 25 (4) ◽  
pp. 354-360 ◽  
Author(s):  
Mary B. Berlyn
Keyword(s):  
Callus Culture ◽  
Dna Content ◽  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Callus Cultures ◽  
Nuclear Volume ◽  
Frequency Distributions ◽  
Volume Measurements ◽  
The Mean ◽  
Undifferentiated Callus

The frequency distributions of DNA content per nucleus were examined in five isonicotinic acid hydrazide (INH) resistant callus lines of tobacco and in developing buds and shoots regenerating from the lines. They were compared with the distribution for a diploid plant, with an estimated 2C value of 7.8 pg. The total range of all the callus cultures was between 5 and 40 pg, with modes between 7 and 16 pg. In the oldest (6 years) callus culture, the mean and standard deviation were lower in the buds developing from the culture than in the undifferentiated callus: however, older shoots again showed a higher mean and more disperse distribution. In contrast, for 4-year-old secondary callus cultures from plants simultaneously regenerated from a second INH-resistant (I 24) line, the mean DNA content per nucleus of the developing buds was higher than that of the undifferentiated callus. Less variation and a more nearly diploid distribution were observed in a 2-year-old callus culture of a fertile plant chosen from the progeny of one of these I 24 plants and in the buds and older shoots regenerated from this culture. Thus, in these five moderately heteroploid cultures a consistent pattern of selection for euploid levels of DNA did not occur during the observed stages of regeneration. Examination of volume as well as DNA content of nuclei in the different tissues showed that variability of nuclear volume measurements, as indicated by coefficients of variation, was correlated with variability of DNA content per nucleus, although measurements of volume and DNA content per individual nucleus were not always highly correlated. It is suggested that high coefficient of variation of nuclear volume, in conjunction with large nuclear size, could serve as a rapid preliminary indicator of highly heterogeneous DNA levels in the nuclear population of Nicotiana cultures.

scholarly journals THE INFLUENCE OF CHROMOSOME CONTENT ON THE SIZE AND SHAPE OF SPERM HEADS IN DROSOPHILA MELANOGASTER AND THE DEMONSTRATION OF CHROMOSOME LOSS DURING SPERMIOGENESIS

Genetics ◽  
1975 ◽  
Vol 79 (2) ◽  
pp. 231-264
Author(s):  
Robert Walter Hardy
Keyword(s):  
Seminal Receptacle ◽  
Three Dimensional ◽  
Sperm Head ◽  
Chromosome Loss ◽  
Head Shape ◽  
Frequency Distributions ◽  
Volume Measurements ◽  
Chromatin Material ◽  
The Mean ◽  
Sperm Nuclei

ABSTRACT The volumes of sperm heads were estimated from three-dimensional reconstructions of serially sectioned bundles of nearly mature spermatid nuclei. Cysts from males in which all sperm are expected to have comparable amounts of chromatin (X/Y and In(3LR)/+) show unimodal frequency distributions of nuclear volumes, whereas cysts from males in which meiotic segregation is expected to deliver unequal amounts of chromatin material to spermatid nuclei show two (XY/O and XY/Y) or more (T(2;3)/+ and C(2L);C(2R)) modes. The mean volumes of the subpopulations in these cases are related in the same proportions as the metaphase lengths of their chromosomal complements. Thus the volumes of sperm nuclei are proportional to their DNA content. Sperm head shape, on the other hand, does not appear to be very sensitive to chromosomal constitution, as heads of different size do not vary greatly in shape.—The numbers of sperm heads in the various size classes in a cyst depart from mendelian expectations; these departures are caused by the elimination, during individualization, of chromosomes contained within micronuclei that are formed in spermatids at the end of the second meiotic division. The effect of this chromosome loss is to increase the proportion of nullosomic gametes in the sperm pool.—The relative frequencies of XY-bearing and nullo-X, nullo-Y sperm in XY/O males were estimated from the volume measurements. Taking this estimate as a measure of the fertilizing population, it is possible to infer from the change in sex ratio over time following insemination, that XY-bearing sperm have an advantage of 1.5 over nullo-X, nullo-Y sperm in leaving the seminal receptacle of the female for fertilization of ova.

Hybrid Design of Isonicotinic Acid Hydrazide Derivatives: Machine Learning Studies, Synthesis and Biological Evaluation of their Antituberculosis Activity

2020 ◽  
Vol 17 (3) ◽  
pp. 365-375
Author(s):  
Vasyl Kovalishyn ◽  
Diana Hodyna ◽  
Vitaliy O. Sinenko ◽  
Volodymyr Blagodatny ◽  
Ivan Semenyuta ◽  
...  
Keyword(s):  
Machine Learning ◽  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Predictive Ability ◽  
Antitubercular Activity ◽  
Biological Evaluation ◽  
Starting Point ◽  
Binary Classifiers ◽  
Synthesis And Biological Evaluation

Background: Tuberculosis (TB) is an infection disease caused by Mycobacterium tuberculosis (Mtb) bacteria. One of the main causes of mortality from TB is the problem of Mtb resistance to known drugs. Objective: The goal of this work is to identify potent small molecule anti-TB agents by machine learning, synthesis and biological evaluation. Methods: The On-line Chemical Database and Modeling Environment (OCHEM) was used to build predictive machine learning models. Seven compounds were synthesized and tested in vitro for their antitubercular activity against H37Rv and resistant Mtb strains. Results: A set of predictive models was built with OCHEM based on a set of previously synthesized isoniazid (INH) derivatives containing a thiazole core and tested against Mtb. The predictive ability of the models was tested by a 5-fold cross-validation, and resulted in balanced accuracies (BA) of 61–78% for the binary classifiers. Test set validation showed that the models could be instrumental in predicting anti- TB activity with a reasonable accuracy (with BA = 67–79 %) within the applicability domain. Seven designed compounds were synthesized and demonstrated activity against both the H37Rv and multidrugresistant (MDR) Mtb strains resistant to rifampicin and isoniazid. According to the acute toxicity evaluation in Daphnia magna neonates, six compounds were classified as moderately toxic (LD50 in the range of 10−100 mg/L) and one as practically harmless (LD50 in the range of 100−1000 mg/L). Conclusion: The newly identified compounds may represent a starting point for further development of therapies against Mtb. The developed models are available online at OCHEM http://ochem.eu/article/11 1066 and can be used to virtually screen for potential compounds with anti-TB activity.

Comparative Investigation on Formation and Accumulation of Rare Phenylpropanoids in Plants and in vitro Cultures of Pimpinella major

1990 ◽  
Vol 45 (6) ◽  
pp. 602-606 ◽  
Author(s):  
B. Merkel ◽  
J. Reichling
Keyword(s):  
Callus Culture ◽  
Nutrient Medium ◽  
Callus Cultures ◽  
Comparative Investigation ◽  
In Vitro Cultures ◽  
Liquid Nutrient Medium ◽  
Whole Plants ◽  
Plant Seedlings

Abstract Unorganized callus and leaf/root-differentiating callus cultures of Pimpinella major have been established in liquid nutrient medium. Their capacity to accumulate rare phenylpropanoids such as epoxy-pseudoisoeugenol tiglate, epoxy-anol tiglate and anol tiglate was compared with that of seedlings and whole plants. The unorganized callus cultures were not able to accumulate any phenylpropanoids. In comparison, the leaf/root-differentiating callus culture promoted the accumulation of epoxy-pseudoisoeugenol tiglate (up to 90 mg/100 g fr.wt.) but not that of anol-derivatives. The accumulated amount of EPT in PMD-SH was comparable with that in plant seedlings.

scholarly journals Curcumin and isonicotinic acid hydrazide functionalized gold nanoparticles for selective anticancer action

2020 ◽  
Vol 607 ◽  
pp. 125484
Author(s):  
Akhela Umapathi ◽  
Navya PN ◽  
Harishkumar Madhyastha ◽  
Mandeep Singh ◽  
Radha Madhyastha ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Isonicotinic Acid Hydrazide ◽  
Functionalized Gold Nanoparticles

scholarly journals Overestimation of grey matter atrophy in glioblastoma patients following radio(chemo)therapy

2021 ◽  
Author(s):  
A. Gommlich ◽  
F. Raschke ◽  
J. Petr ◽  
A. Seidlitz ◽  
C. Jentsch ◽  
...  
Keyword(s):  
Brain Tumour ◽  
Contralateral Hemisphere ◽  
Mr Images ◽  
Segmentation Accuracy ◽  
Volume Measurements ◽  
Radiation Induced ◽  
The Mean ◽  
Changes Over Time ◽  
Grey Matter Atrophy ◽  
Abnormal Tissue

Abstract Objective Brain atrophy has the potential to become a biomarker for severity of radiation-induced side-effects. Particularly brain tumour patients can show great MRI signal changes over time caused by e.g. oedema, tumour progress or necrosis. The goal of this study was to investigate if such changes affect the segmentation accuracy of normal appearing brain and thus influence longitudinal volumetric measurements. Materials and methods T1-weighted MR images of 52 glioblastoma patients with unilateral tumours acquired before and three months after the end of radio(chemo)therapy were analysed. GM and WM volumes in the contralateral hemisphere were compared between segmenting the whole brain (full) and the contralateral hemisphere only (cl) with SPM and FSL. Relative GM and WM volumes were compared using paired t tests and correlated with the corresponding mean dose in GM and WM, respectively. Results Mean GM atrophy was significantly higher for full segmentation compared to cl segmentation when using SPM (mean ± std: ΔVGM,full = − 3.1% ± 3.7%, ΔVGM,cl = − 1.6% ± 2.7%; p < 0.001, d = 0.62). GM atrophy was significantly correlated with the mean GM dose with the SPM cl segmentation (r = − 0.4, p = 0.004), FSL full segmentation (r = − 0.4, p = 0.004) and FSL cl segmentation (r = -0.35, p = 0.012) but not with the SPM full segmentation (r = − 0.23, p = 0.1). Conclusions For accurate normal tissue volume measurements in brain tumour patients using SPM, abnormal tissue needs to be masked prior to segmentation, however, this is not necessary when using FSL.

scholarly journals THE ISOLATION AND PROPERTIES OF THE ISONICOTINIC ACID HYDRAZIDE ANALOGUE OF DIPHOSPHOPYRIDINE NUCLEOTIDE

1954 ◽  
Vol 209 (2) ◽  
pp. 467-484 ◽  
Author(s):  
Leonard J. Zatman ◽  
Nathan O. Kaplan ◽  
Sidney P. Colowick ◽  
Margaret M. Ciotti
Keyword(s):  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Isonicotinic Acid Hydrazide

scholarly journals Growth and population biology of the sand-bubbler crab Scopimera crabricauda Alcock 1900 (Brachyura: Dotillidae) from the Persian Gulf, Iran

2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Sana Sharifian ◽  
Vahid Malekzadeh ◽  
Ehsan Kamrani ◽  
Mohsen Safaie
Keyword(s):  
Persian Gulf ◽  
Population Biology ◽  
Slow Growth ◽  
Carapace Width ◽  
Population Data ◽  
Natural Mortality ◽  
Frequency Distributions ◽  
Iranian Coast ◽  
The Mean ◽  
The Persian Gulf

Abstract Background Dotillid crabs are introduced as one common dwellers of sandy shores. We studied the ecology and growth of the sand bubbler crab Scopimera crabricauda Alcock, 1900, in the Persian Gulf, Iran. Crabs were sampled monthly by excavating nine quadrats at three intertidal levels during spring low tides from January 2016 to January 2017. Results Population data show unimodal size-frequency distributions in both sexes. The Von Bertalanffy function was calculated at CWt = 8.76 [1 − exp (− 0.56 (t + 0.39))], CWt = 7.90 [1 − exp (− 0.59 (t + 0.40))] and CWt = 9.35 [1 − exp (− 0.57 (t + 0.41))] for males, females, and both sexes, respectively. The life span appeared to be 5.35, 5.07, and 5.26 years for males, females, and both sexes, respectively. The cohorts were identified as two age continuous groups, with the mean model carapace width 5.39 and 7.11 mm for both sexes. The natural mortality (M) coefficients stood at 1.72 for males, 1.83 for females, and 1.76 years−1 for both sexes, respectively. The overall sex ratio (1:0.4) was significantly different from the expected 1:1 proportion with male-biased. Recruitment occurred with the highest number of annual pulse once a year during the summer. Conclusions The results, which show slow growth, emphasize the necessity of proper management for the survival of the stock of S. crabricauda on the Iranian coast of the Persian Gulf.

Reference points for the length-based indicator Lmax5% for use in the assessment of data-limited stocks

2019 ◽  
Vol 76 (7) ◽  
pp. 2125-2139 ◽  
Author(s):  
Tanja Miethe ◽  
Yves Reecht ◽  
Helen Dobby
Keyword(s):  
Life Histories ◽  
Stock Assessment ◽  
Reference Points ◽  
Length Frequency ◽  
Frequency Distributions ◽  
Simulation Tools ◽  
Spawning Potential Ratio ◽  
The Mean ◽  
Commercial Sources ◽  
Length Frequency Data

Abstract In the absence of abundance indices from scientific surveys or commercial sources, reliable length frequency data from sampled commercial catches can be used to provide an indirect assessment of fishing mortality. Length-based indicators are simple metrics which describe length frequency distributions. The length-based indicator Lmax5%, the mean length of the largest 5% of individuals in the catch, combined with appropriately selected reference points, can be used to evaluate the presence of very large individuals in the catch and hence determine exploitation level. Using analytical per-recruit models, we derive reference points consistent with a spawning potential ratio of 40%. The reference points depend on the life history parameters for natural mortality, maturity, and growth (M, Lmat, L∞, k, CVL∞). Using available simulation tools, we investigate the sensitivity of the reference points to errors in these parameters and explore the usefulness of particular reference points for management purposes for stocks with different life histories. The proposed reference points are robust to uncertainty in length at first capture, Lc, and take into account the maturation schedule of a species. For those stocks with high M/k ratios (&gt;1), Lmax5%, combined with the appropriate reference point, can be used to provide a data-limited stock assessment.

scholarly journals Lysyl oxidase activity and elastin/glycosaminoglycan interactions in growing chick and rat aortas.

1987 ◽  
Vol 105 (3) ◽  
pp. 1463-1469 ◽  
Author(s):  
C Fornieri ◽  
M Baccarani-Contri ◽  
D Quaglino ◽  
I Pasquali-Ronchetti
Keyword(s):  
Hydrophobic Interactions ◽  
Isonicotinic Acid ◽  
Lysyl Oxidase ◽  
Acid Hydrazide ◽  
Elastic Fibers ◽  
Amino Groups ◽  
Lysine Residues ◽  
Oxidase Inhibition

Hydrophobic tropoelastin molecules aggregate in vitro in physiological conditions and form fibers very similar to natural ones (Bressan, G. M., I. Pasquali Ronchetti, C. Fornieri, F. Mattioli, I. Castellani, and D. Volpin, 1986, J. Ultrastruct. Molec. Struct. Res., 94:209-216). Similar hydrophobic interactions might be operative in in vivo fibrogenesis. Data are presented suggesting that matrix glycosaminoglycans (GAGs) prevent spontaneous tropoelastin aggregation in vivo, at least up to the deamination of lysine residues on tropoelastin by matrix lysyl oxidase. Lysyl oxidase inhibitors beta-aminopropionitrile, aminoacetonitrile, semicarbazide, and isonicotinic acid hydrazide were given to newborn chicks, to chick embryos, and to newborn rats, and the ultrastructural alterations of the aortic elastic fibers were analyzed and compared with the extent of the enzyme inhibition. When inhibition was greater than 65% all chemicals induced alterations of elastic fibers in the form of lateral aggregates of elastin, which were always permeated by cytochemically and immunologically recognizable GAGs. The number and size of the abnormal elastin/GAGs aggregates were proportional to the extent of lysyl oxidase inhibition. The phenomenon was independent of the animal species. All data suggest that, upon inhibition of lysyl oxidase, matrix GAGs remain among elastin molecules during fibrogenesis by binding to positively charged amino groups on elastin. Newly synthesized and secreted tropoelastin has the highest number of free epsilon amino groups, and, therefore, the highest capability of binding to GAGs. These polyanions, by virtue of their great hydration and dispersing power, could prevent random spontaneous aggregation of hydrophobic tropoelastin in the extracellular space.

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